Save Wave duplicate sample

[DigitalWhiteByte]

I ran into this strange thing,
I created a wav file with the sequence of samples ranging in value from 00 to FF
(in hexadecimal values​​, those written in binary file)
I loaded this file wav and I just resaved from synthmaker, after the value 7F,
the samples are repeated in pairs 81 81 83 83. should be 80 81 82 83 ect.
There is a problem of approximation in the primitive SAVE WAVE?
It also seems that the 8-bit WAV files are not loaded correctly.
If someone tells me this thing send a bug report.

[DigitalWhiteByte]

After some tests are now more puzzled than before ....
Surely there is a problem of approximation of float numbers,
but I could not tell if it is in the primitive "WaveFile" or primitive "SaveWave".
This perplexes me.

[trogluddite]

Wonder if t related to the use of banker's rounding?
i.e. rndint (x-0.5); would be expected to 'always round 'x' downwards, except that alternate integer values of 'x' will then round to the same output value.
Though that doesn't explain why values <7F should still be correct.